An addressable, implantable microstimulator is substantially encapsulated within a hermetically-sealed housing inert to body fluids, and of a size and shape capable of implantation in a living body, by expulsion through a hypodermic needle. Power and information for operating the microstimulator is received through a modulated, alternating magnetic field in which a coil is adapted to function as the secondary winding of a transformer. Electrical energy is stored in capacitor means and is released into the living body by controlled, stimulating pulses which pass through body fluids and tissue between the exposed electrodes of the microstimulator. Detection and decoding means within the microstimulator are provided for controlling the stimulating pulses in accordance with the modulation of the received, alternating magnetic field. Means for controllably recharging the capacitor is provided.